Plasma Chemistry and Plasma Processing, Vol.28, No.6, 715-728, 2008
Surface Modification of Silicone Rubber by CF4 Radio Frequency Plasma Immersion
Silicone rubber samples were treated by CF4 capacitively coupled plasma at radio frequency (RF) power of 60, 100 and 200 W for a treatment time up to 20 min under CF4 flow rate of 20 sccm, respectively. Static contact angle, ATR-FTIR and XPS, and AFM were employed to characterize the changes of surface on hydrophobicity, functional groups, and topography. The results indicate the static contact angle is improved from 100.7 to 150.2, and the super-hydrophobic surface, which corresponds to a static contact angle of 150.2, appears at RF power of 200 W for a 5 min treatment time. It is suggested that the formation of super-hydrophobic surface is ascribed to the co-action of the increase of surface roughness created by the ablation reaction of CF4 plasma and the formation of [-SiF (x) (CH3)(2-x) -O-] (n) (x = 1, 2) structure produced by the direct attachment of F atoms to Si.